Green Mountain Audio

Speaking as a woodworker, veneering marble isn’t that straightforward. Since you are only doing one side, and since the affects of environment on marble and wood are very different, choose wisely and test. A self-balanced veneer - two sheets stacked in opposite directions - is more stable than a raw veneer. A paper backed veneer is even more stable. Marble is a strange product with adhesives - so contact cement may be out. I use heat lock - but have no idea how it would work with the marble. 

It isn’t really marble. It is a synthetic resin. I figured I would practice different techniques on the underside and see what sticks best. The material is very similar to cultured marble shower walls. I believe if roughed up it will hold. I generative titebond on both substrates, allow to dry, and then reactivate with an iron. I prefer this over contact cement as you can adjust for fit. 

Get in touch with the Speaker Exchange in Tampa, they can reform the drivers. They have done excellent work for me on JBL and Tannoy drivers. 

Congrats on the speakers. Over the years I owned Imagos, Callistos and Continuum C3. All were excellent performers. Roy was a true genius in my book and a real gentleman.

Most bigger cities that I know of have PROFESSIONALs that are skilled at rebuilding drivers—everything from new surrounds to new cones and even coils. This might not be the exact same quality speaker that was in it originally when you are done but you actually take the chance on improving them with new modern materials and compounds being used. Do your research first and even get references. You might want to go the extra 100 miles to get a better tech to do the right job.